451945021 has 4 divisors (see below), whose sum is σ = 493030944. Its totient is φ = 410859100.

The previous prime is 451944953. The next prime is 451945031. The reversal of 451945021 is 120549154.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 451945021 - 2⁹ = 451944509 is a prime.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (451945031) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 20542945 + ... + 20542966.

It is an arithmetic number, because the mean of its divisors is an integer number (123257736).

Almost surely, 2^451945021 is an apocalyptic number.

It is an amenable number.

451945021 is a deficient number, since it is larger than the sum of its proper divisors (41085923).

451945021 is a wasteful number, since it uses less digits than its factorization.

451945021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 41085922.

The product of its (nonzero) digits is 7200, while the sum is 31.

The square root of 451945021 is about 21258.9985888329. The cubic root of 451945021 is about 767.4119106531.

The spelling of 451945021 in words is "four hundred fifty-one million, nine hundred forty-five thousand, twenty-one".